Angular4 copy object without reference?

Question

Inside a component I tried to copy an object from a service that could be modified inside the component, but should stay in the service.

private test;

public ngOnInit(): {
  console.log(this.someService.test.someProperty) //'old'
  this.test = this.someService.test;

  //not working as well?!
  //this.test = Object.assign({}, this.someService.test);
  //this.test = Object.create(this.somerService.test);

  this.changeTest();
}

public changeTest(): void {
  this.test.someProperty = 'new';
}

after the init both, this.test.someProperty as well as this.someService.test.someProperty are changed to new even though the last should stay old?

Why is that happening, and how to only change properties of this.test

Answer 1

Actually Object assign works as in your example. Created plunker to prove it

  this.test = Object.assign({}, this.someService.test);